This is a second revision of an application for competitive renewal of MH56120, a research program for the study of neural correlates of childhood sexual abuse-related posttraumatic stress disorder (PTSD) in women. In the initial funding period studies used magnetic resonance imaging (MRI) and position emission tomography (PET) to show smaller hippocampal volume and failure of hippocampal activation with memory tasks in women with abuse-related PTSD. The PI now proposes to continue studies of neural correlates of abuse-related PTSD with a focus on the amygdala, which has been shown in animal studies to play a critical role in conditioned fear responses, and the medial prefrontal cortex, which is felt to be involved in extinction of fear responses. Preliminary data collected by the PI with PET showed increased amygdala activation with acquisition of conditioned fear responses, and a failure of medial prefrontal cortical activation during extinction of fear responding, in women with abuse-related PTSD. Newly analyzed skin conductance (SC) data from this study confirmed the ability of this paradigm to produce conditioned responses. The PI now proposes to compare neural and SC correlates of conditioned fear responses in women with childhood sexual abuse-related PTSD compared to abused women without PTSD, non-abused women without PTSD, and non-abused women with PTSD from adult civilian trauma. The specific aims of this competitive renewal are therefore to: 1) compare amygdala activation during acquisition of fear responding between PTSD and comparison groups. We hypothesize increased amygdala activation during acquisition of fear responses in PTSD; 2) compare medial prefrontal cortical function during extinction of fear responses between PTSD and comparison groups. We hypothesize a failure of medial prefrontal cortical activation during extinction in PTSD; 3) assess the relationship between SC responses and brain activation. We hypothesize increased SC responses will correlate with increased amygdala/decreased prefrontal function in PTSD. Secondary exploratory analyses will compare brain activation patterns in early onset to adult onset PTSD. [unreadable] [unreadable]